Sheet material stamping die



A ril 21, 1964' A. E. PAYNE $129,744

: SHEET MATERIAL STAMPING DIE Filed June 26; 1959 5 Sheets-{Sheet 1 PRIOR ART FIG-l 9 FIG-2 INVENTOR.

ALBERT E. PAYNE ATTORNEYS April 21, 1964 A. E. PAYNE 3,129,744

SHEET MATERIAL STAMPING DIE Filed June 26, 1959 4, 5 Sheets-Sheet 2 III {I I 24 [I ll I I/ I l t l 3i 32'.

H674 PRIOR ART 27 28 I CLEARANCE 3o 2a g PUNCH m [Appaox.' PENETRATION H675 BREAK I TOCK SLUG DIE

FIG-6 ALBERT E. V BY7 g ATTORNEYS April 21, 1964 A. E. PAYNE 3,129,744

SHEET MATERIAL STAMPING DIE Filed June 26, 1959 5 Sheets-Sheet 3 INVENTOR.

ALBERT E. PAYNE F|G."|| ATTORNEYS April 21, 1964 Filed June 26, 1959 A. E. PAYNE SHEET MATERIAL STAMPING DIE 5 Sheets-Sheet 4 'wFlGr l2 INVENTOR.

III

ALBERT E. PAYNE BY 07 2 d 7/ g ATTORNEYS I FIG-I3 A ril 21, 1964 A. E. PAYNE 3,129,744

SHEET MATERIAL STAMPING DIE Filed June 26, 1959 5 Sheets-Sheet 5 INVEN TOR. ALBERT E PAYNE FIG-l5 81 BY W1 ATTORNEYS United States Patent 3,129,744 SHEET MATERIAL STAMPING DIE Albert E. Payne, Jamestown Road, Rte. 4, Springfield, Ohio Filed June 26, 1959, Ser. No. 823,173 3 illaims. (Cl. 153-2) This invention relates to sheet material stamping dies and the production of such dies.

The invention has as a principal object the provision of dies having the desirable characteristics of good tensile strength and hardness, wear resistance, and an excellent capacity for resisting distortion. Such dies in the practice of the invention are attained economically even though complex contours are involved in many instancesand the dies are attained with a minimum number of components providing for very considerable die economy and a long service life.

The invention has an important object the provision of a novel method of manufacturing sheet material stamping dies; such dies for most purposes are composed of a considerable number of parts, each of which is heat treated prior to incorporation in the assembled die. In the die of this, invention the die and die shoe are integral and are readily formed, for example, by milling the die shoe appropriately to the die contour, such provides for a strengthened die and in addition eliminates dowels, holding screws and the like.

The invention has as a further object the provision of a novel die structure in which opposed surfaces of a die shoe are provided with surface configurations adapted to complementary metal stamping operations, such as blanking and forming.

The invention will be more fully understood by reference to the following detailed description and accompanying drawings wherein:

FIGURE 1 is a fragmentary sectional view in elevation of a conventional sheet material stamping procedure of the prior art;

FIGURE 2 is a comparison view illustrating the procedure of FIGURE 1 effected in accordance with the die construction of the present invention;

FIGURE 3 is a plan view illustrating a method of guiding sheet material to a stamping die in accordance with the present invention;

FIGURE 4 is an elevational view partly in section illustrating a punching operation performed with conventional equipment of the prior art;

FIGURE 5 is a comparative view illustrating structure in accordance with the invention for effecting the procedure of FIGURE 4, and particularly stressing the punch structure;

FIGURE 6 is a schematic view illustrating the mode in which metal separates when punched, as illustrated in FIGURE 5;

FIGURE 7 is a perspective view with parts broken away illustrating the sheet material being stamped between upper and lower die shoes, having the die parts formed integral therewith, and further illustrating the upper die shoe as being reversible;

FIGURE 8 is a sectional view in elevation illustrating in further detail the structural arrangement of FIG- URE 7;

FIGURE 9 is a view similar to that of FIGURE 8 but illustrating the upper shoe in reverse position for effecting a forming operation;

FIGURE 10 is a perspective View illustrating a die of the prior art particularly including the usual hold-down screws and dowels;

FIGURE 11 is a perspective view similar to that of FIGURE 10 but illustrating a die in accordance with the present invention wherein the hold-down screws and dowels are eliminated;

FIGURE 12 is a view of an upper die shoe having a die formed integral therewith;

FIGURE 13 is a View of the lower die shoe and die in cooperation with the structure of FIGURE 12;

FIGURE 14 is an elevational view partly in section illustrating the dies of FIGURES 12 and 13 mounted in position for effecting a stamping operation; and

FIGURE 15 is a view in perspective illustrating a blanking die in which the die portion projects from the shoe and is contoured in appropriate manner for effecting the die operation.

Referring now to the drawings more in detail, the numeral 1' in FIGURE 1 designates a press platen having secured thereto at 2' an upper shoe of a die set, the shoe being retained on the platen through the medium of shank 3'. The numeral 4' designates the lower shoe which is provided to be retained on the press by means of clamping ears 5'. Standard bolts 7', 8' serve to retain the die sections on the shoes. A blanking punch 11 of conventional structure is provided and is retained by bolts as at 10 and receives dowels as at 9'.

Pressure pads 12 form with the spring 13' a stripper; a punch 14' is itself suitably backed by a back-up plate 15. A lower stripper spring is designated at 16' and the lower die is designated at 17. The numeral 18' indicates a die button for retention of the lower punch portion 19'.

As will be noted from the drawing in FIGURE 1, the stock 2t), guided by guide 21, is passed through the press and the operations of blanking out the piece 22' and of punching a hole with the punch 14' are readily effected. However, a great plurality of components are necessary for this purpose.

Referring now to FIGURE 2, the platen 1 has secured thereto an upper die shoe 2 which has formed integral with the lower surface thereof at 3 a female portion of the blanking die. The numeral 4 designates the lower shoe which at 5 has formed thereon the male portion of the blanking die. The portions 3, 5 are formed directly in the die shoes by milling, usually. As will be noted hereinafter end milling, side milling, grinding and the like, serve usually to provide complete formation of the die in the die block.

Referring now again to FIGURE 2, guide pins are provided at 6 and serve to align the upper and lower portions of the die. Hold-down slots are designated at 7 and conventional hold-down clamps indicated at 8 are effective to retain the die sections on the press. As indicated these are conventional toe clamps and accordingly it is not necessary to describe the same in further detail.

Provision for positive knockout may be included, if desired, as indicated at 9. The punching operation is readily effected after the blanking by provision of the punch at 10. Thenumeral 11 designates the material on which the blanking and punching operations are effected, while the numeral 12 designates the rubber stripper.

Accordingly, as will be readily seen from a comparison of FIGURES 1 and 2, the formation of the die contours integral with the shoes is effective to eliminate a multiplicity of elements, while at the same time providing a more rigid die body. Further, the dies themselves, as will be noted, are substantially completely formed of a unitary mass of metal prior to heat treatment, and accordingly a relatively large mass of metal is subjected to the heat treating operation which is employed to harden the metal suitably. This results in improved accuracy in the die parts and is in direct contrast to the usual procedure of die assembly wherein components are first heat treated and then assembled. Further, the large mass of the heat-treated metal is of assistance in the conduct of any touch-up operation to finish the dies.

As illustrated in FIGURE 3 the guide pin 6 may very suitably serve the purpose of guiding the stock 11 in such manner that a minimum of waste is achieved. In this instance the die indicated at 14 includes a cavity 15 and a punch opening 16. Further, there are provided scrap cutters designated at I7, 18, while the numeral 1a in FIGURE 3 indicates areas from which material has been blanked out. Hold-down slots are provided at 29. The feature of utilizing the guide pins as guides for the passage of the sheet material to be stamped is effective to materially reduce cost, as mill stock may thus be employed and a minimum of scrap achieved.

Referring now to FIGURES 4 and 5, in FIGURE 4 an upper shoe is shown at 24' and is provided with dowels 25', and hold-down screws 26' for the retention of a punch holder which is designated at 27. This punch structure includes the back-up plate 28' and the punch 29'. The lower shoe for this assembly in FIGURE 4 is indicated at 30' and a pressure pad 31 surmounts the lower shoe, and the stock 32 is punched out as the knife edge of the punch shears the material at the die button 33'.

Referring now to FIGURE 5, the numeral 24 designates an upper shoe which has formed integral therewith the punch 25, and which upper shoe is shouldered at 26 to provide for receipt of a rubber pad 27, which is positioned over the stock 28, in the course of the punching operation. The lower shoe is designated at 29 and has a cavity 30 provided therein for passage of the punched material therethrough, this passage being similar to the cavity 34- of FIGURE 4.

It will be appreciated from a consideration of FIG- URE that but a very slight projection of the punch is required, but that nevertheless considerable strength is attained due to the integral nature of the shoe and punch.

FIGURE 6 fairly illustrates that in the utilization of the structure of FIGURE 5 only about one-third of the metal of the punch actually penetrates the stock in a cutting action; the remainder is broken essentially as clearly indicated in the drawing.

Referring now to FIGURE 7, a further embodiment of the die structure of invention is illustrated therein and is designated generally at 4t). As will be noted from the figure the die includes an upper shoe 41 and a lower shoe 42. The upper shoe 41 has formed integral therewith, as indicated at 43, a blanking die, while the lower shoe, as indicated at 44, has formed integral therewith punch 43. Rubber strippers are designated, respectively, at 45 and 46. The stock 47 passes through the die as indicated in a conventional blanking operation; however, it is to be noted that the upper shoe 41 includes a forming die structure 48.

In FIGURE 8 the blanking operation is indicated. For this purpose the lower die shoe may have a forming die portion designated at 49 on the lower side of the shoe, or it may include the die portion 50 directly in the upper face of the lower die shoe and beneath the blanking portion. If only the forming die portion 49 were used then both structures, that is, the upper and lower shoes, would be reversed to achieve the forming operation indicated in FIGURE 9. However, in the present instance the specific description is directed to utilizing the forming die portion 50 in cooperation with the forming die portion 48 to effect the forming operation of FIGURE 9.

The numerals clearly designate the structural arrangement both for effecting the punching and the forming operations.

FIGURES and 11 clearly illustrate structures both of the prior art and in accordance with the invention wherein the advantages of the structure of invention are demonstrated.

In the prior art the structure shown in FIGURE 10, the back-up plate 55 would have supported thereon the die structure 56, and there would be included the dowel 57 for alignment and the screws 58' for effecting holding of the various pieces of the die. Further, as may be noted the die of FIGURE 10 is a multi-piece die and each piece requires a plurality of dowels and screws, all of which are not shown in order to avoid complication of the figure. Further, because of the corner structure considerable machine work is required, and in addition each of the pieces must be separately heat treated.

In contrast to the structure of FIGURE 10 a structure provided in accordance with the present invention, as illustrated in FIGURE 11, may have a shoe 65, a female die 66, formed by end milling the die portion from the shoe, there being no necessity for dowels or hold-down screws in the manner set out in FIGURE 10. Also as clearly indicated by numerals 67 the contours may be well rounded or as at 68 the cutting edges may be linear.

FIGURES 12, 13 and 14 illustrate a die structure in which a plurality of operations of varying types are performed, as may be clearly seen from a consideration of the drawings.

As will be noted from FIGURES 12 and 13, the numeral 749 in FIGURE 12 designates a die shoe having guide openings 71 and a die designated at 72, the die being formed by the milling out in appropriate fashion of metal of the die shoe, as may be clearly seen from FIG- URE 14.

In FIGURE 13 the die shoe 73 is provided with guide posts 74 for cooperation with the openings 71 of the die shoe.

The die forms the lower element of the die structure assembly, as may be clearly seen from FIGURE 14. In FIGURE 14 the numeral 76 indicates the punch which cooperates with the recess 78 of the die punch 77 cooperates with the die opening at 79, while the punch 80 cooperates with the die opening at 81. The numeral 82 designates cavities below the respective openings in the die 75 for the passage of material struck out from sheet material being processed. Also in FIGURE 14 the numeral 83 designates the rubber stripper component.

It is to be noted that after formation of the die shoes having the integral dies, as shown in FIGURES 12 and 13, the die structures are heat treated in a conventional manner; but due to the great mass of metal the accuracy of the die is improved by the heat treating operation.

This it is to be noted, is in direct contrast to the usual die structures wherein the die is made up of a multiplicity of components which are separately heat treated prior to assembly. Further, it may be noted that all of the usual functions of press dies in sheet material work may be performed with the die structure of invention. For example, the operations of extruding, forming, dimpling, embossing, piercing, blanking, notching, lancing, drawing and those die operations winch are singular or progressive may be performed with the structure of invention.

Reference may now be had to FIGURE 15 wherein the numeral 85 designates the massive body of metal which forms the die shoe having the die 86. As may be noted clearly from the drawing contours of various shape are readily formed in the mass of metal to produce the die 86, the numeral 87 designating a portion of the configuration.

While it is customary with some dies to fillet the area connecting the die shoe with the die for the purposes of achieving improved strength, such is not necessary in the present case.

Further, due to the very considerable strength imparted by the integral feature of the die and die shoe, the die itself may be of somewhat lesser thickness than is customary with dies which are retained to the shoe by screws. and the like.

A die such as that shown in FIGURE 15, while it has one working face provided with the die structure, and as described in connection with FIGURES 7-9, inclusive, have the opposite working face provided with a forming die; for example, in connection with the formation of the die structures, it is to be noted that any usual metal entployed in the formation of dies, for example, steels, are suitable.

Further, relatively simple milling, grinding and similar operations Will effect the formation of the necessary contours of the die in most instances.

Where the term die is employed in connection with the specification and the appended claims, it will be understood to include each of the cooperating members of the set commonly used in press die work, that is, the upper and lower members.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and accordingly, it is desired to comprehend such modifications within this invention as may fall Within the scope of the appended claims.

What is claimed is:

1. A composite die structure for blanking and forming sheet metal comprising; a pair of first and second metal die shoes aligned together, said first shoe having a male die portion projecting upwardly from and integrally formed with said first shoe, said second shoe having a female die portion integrally formed with said second shoe and having a recess formed therein for receiving the said male die for cutting sheet metal, and said male and female die portions each having a forming die portion integrally formed therewith and selectively cooperable for use in a forming operation subsequent to the cutting operation performed by the said male and female die portions, said shoes, said male and female die portions, and said forming die portions all having the same heat treatment characteristics prior to using said die structure.

2. A composite ie structure for blanking and forming sheet metal comprising; a pair of first and second metal die shoes aligned together, said first shoe having a cutting male die portion projecting upwardly from and integrally formed with said first shoe, said second shoe having a cutting female die portion integrally formed with said second shoe and having a recess formed therein for receiving the said male die portion for cutting sheet metal, said male die portion having a forming die portion integrally formed in face thereof, said female die portion having a forming die portion integrally formed on the reverse side of said recess, both said forming die portions being selectively cooperable for use in a forming operation subsequent to the cutting operation performed by the said male and female cutting die portions, said shoes, said male and female cutting die portions, and said forming die portions all having the same heat treatment characteristics prior to using said die structure.

3. A composite die structure for blanking and forming sheet metal comprising; a pair of first and second metal die shoes aligned together, said first shoe having a cutting male die portion projecting upwardly from and integrally formed with said first shoe, said second shoe having a cutting femaledie portion integrally formed with said second shoe and having a recess formed therein for receiving the said male die portion for cutting sheet metal, said male die portion having a forming die portion integrally formed in the reverse side from the portion projecting upwardly, said female die portion having a forming die portion integrally formed on the reverse side of said recess, both said forming die portions being selectively cooperable for use in a forming operation subsequent to the cutting operation performed by the said male and female die portions, said shoes, said male and female cutting die portions, and said forming die portions all having the same heat treatment chm'acteristics prior to using said die structure.

References Cited in the file of this patent UNITED STATES PATENTS Re. 6,163 Britton Dec. 8, 1874 170,076 Geldreich Nov. 16, 1875 936,673 Shuman Oct. 12, 1909 968,122 Carr Aug. 23, 1910 1,458,599 Stafford June 12, 1923 1,552,747 Klumpp Sept. 8, 1925 1,801,490 Falstrom Apr. 21, 1931 2,009,660 Irmis July 30, 1935 2,232,742 Smith Feb. 25, 1941 2,456,749 Steibel Dec. 21, 1948 2,703,023 Sarno Mar. 1, 1955 2,743,629 Pellegrino May 1, 1956 2,850,924 Hempel Sept. 9, 1958 2,952,174 Broske Sept 13, 1960 

1. A COMPOSITE DIE STRUCTURE FOR BLANKING AND FORMING SHEET METAL COMPRISING; A PAIR OF FIRST AND SECOND METAL DIE SHOES ALIGNED TOGETHER, SAID FIRST SHOE HAVING A MALE DIE PORTION PROJECTING UPWARDLY FROM AND INTEGRALLY FORMED WITH SAID FIRST SHOE, SAID SECOND SHOE HAVING A FEMALE DIE PORTION INTEGRALLY FORMED WITH SAID SECOND SHOE AND HAVING A RECESS FORMED THEREIN FOR RECEIVING THE SAID MALE DIE FOR CUTTING SHEET METAL, AND SAID MALE AND FEMALE DIE PORTIONS EACH HAVING A FORMING DIE PORTION INTEGRALLY FORMED THEREWITH AND SELECTIVELY COOPERABLE FOR USE IN A FORMING OPERATION SUBSEQUENT TO THE CUTTING OPERATION PERFORMED BY THE SAID MALE AND FEMALE DIE PORTIONS, SAID SHOES, SAID MALE AND FEMALE DIE PORTIONS, AND SAID FORMING DIE PORTIONS ALL HAVING THE SAME HEAT TREATMENT CHARACTERISTICS PRIOR TO USING SAID DIE STRUCTURE. 